Contents

Description

The European Organisation for the Safety of Air Navigation (EUROCONTROL) ASM Improvement Initiative aims to deliver concrete ASM improvements in 2009 and 2011. One of the objectives is to implement new procedures to support the optimisation of airspace usage for both civil and military airspace users.
The Preliminary Safety Case (PSC) Report provides some of the evidence to support the top-level claim that the activation/deactivation of airspace via application of ASM/ATFCM Procedure 3 contributes to the achievement of an acceptable level of safety in the operating environment within which it is implemented.

In principle ASM/ATFCM Procedure 3 is designed to reduce the amount of air traffic requiring tactical management in the execution phase of flight. The impact of each request is assessed at a network level and the final allocation of airspace is decided by the Airspace Management Cell (AMC) taking into account the impact. In addition time limits in the procedure specify a minimum of lead time of two hours during which airspace users are notified of the route closures. During this time a significant portion of the affected flight plans will be cancelled and re-filed. Therefore the volume of traffic that the ATC is required to tactically manage for the duration of the closure will be significantly reduced potentially reducing the workload on ATC and reducing risk.

For local implementation States will need to clearly define how their implementation of ASM/ATFCM Procedure 3 differs from current operations. This may differ from State to State depending on whether ASM/ATFCM Procedure 3 has been modified or tailored from the version developed by EUROCONTROL and documented in the EUROCONTROL ASM Handbook.

Context

The Dynamic Management of the European Airspace Network (DMEAN) Concept of Operations calls for a collaborative airspace, flow and capacity management to optimise the use of airspace and the existing en-route and airport capacities through the enhancement of ASM/ATFCM processes. This means the strengthening of the relationship between Airspace Management Cells (AMCs), Flow Management Positions (FMPs) and the Central Flow Management Unit (CFMU) through the establishment of more efficient coordination mechanisms. The aim is to minimise the impact of any disruptions (e.g. route closure) and to take advantage of opportunities such as additional route availability in order to enable all airspace users to conduct efficient real-time operations.

Three main weaknesses were identified with today’s situation:

National airspace allocation decisions are not always coordinated with neighbours (they are still not considered from a network perspective).

There is no possibility for aircraft operators to optimise flight plans on the basis of airspace opportunities (notification of addition route availability is frozen on the day before operations and there is no adequate notification of route updates on the day of operations).

Possibilities on the day of operations to activate non-planned military areas are limited.

On the basis of these three main weaknesses, three procedures have been developed:

ASM/ATFCM Procedure 1: Optimising capacity usage via an assessment on the impact on the network of expected airspace allocation during activities the day before operation.

ASM/ATFCM Procedure 2: Making better use of airspace opportunities (alteration of airspace restrictions, increase route availability) on the day of operations in order to provide additional route options to aircraft operators.

ASM/ATFCM Procedure 3: Ensuring more flexible use of airspace on the day of operations in order to better respond to ad-hoc military needs while minimising the negative impact on the network.

Live Trials were carried out in November 2008 and confirmed that Procedures 1 and 2 were mature enough to be included in the ASM Handbook. During preparation for the trials it became apparent that safety issues associated with Procedure 3 ‘Unplanned activation of TSAs/|TRAs’, were more complex than originally envisaged and as such further work was required to assess the safety hazards and develop a Preliminary Safety Case. These safety issues are documented in the November Live Trial Final Report

The operational driver behind the development of ASM/ATFCM Procedure 3 is to address the ‘weaknesses in the current system where possibilities for the military to activate nonplanned TSAs/|TRAs’ on the day of operations are limited. The operational objective for introducing the procedure is that it will complement already existing procedures to optimise the use of airspace while minimising the impact of any disruptions (i.e. route closures) and therefore enable all airspace users to conduct efficient real-time operations i.e. the primary aim is to increase capacity.

Top Level Claim

The activation/deactivation of airspace via the applications of ASM/ATFCM Procedure 3 contributes to the achievement of an acceptable level of safety in the operating environment within which it is implemented.
This claim is made within the context that, the operational environment is defined and subject to any stated identified issues, assumptions, caveats and limitations.

General Assumptions

The safety of ASM/ATFCM Procedure 3 will be assessed as a generic procedure independent of implementation. Individual States are responsible for assuring an overall acceptable level of safety when implementing the procedure

Current operations without the implementation of ASM/ATFCM Procedure 3 are considered tolerably safe.

CFMU will update the ENV database on receipt of the UUP in a timely manner.

Civil Airspace Users are informed of CDR closures via the Conditional Route Availability Message (CRAM) and are also available via the NOP Portal.

The Conditional Route Availability Message (CRAM) is available on the Central Flow Management Unit (CFMU) NOP Portal in HTML format and a hardcopy is also sent to all registered addresses in ATS Data Exchange Presentation (ADEXP) format via the AFTN Network.

CDR Closure and Route Availability information is promulgated by Central Flow Management Unit (CFMU) via the Conditional Route Availability Message (CRAM) once a day. Further changes will be disseminated via AIM. It is noted that an additional method of information dissemination, an eAMI, is planned to be implemented in the future however; consideration of eAMI messages are outside the scope of this safety assessment activity